This invention relates to a replaceable wear element, assembly and method, and, more particularly, an assembly for installation on the wearable part of a structure engageable with abrasive material.
This invention is an improvement on co-owned U.S. Pat. No. 4,716,666. In that patent, a pair of spaced apart dovetails were employed to provide a readily replaceable wear element--as for the underside of an excavating bucket. The four dovetail surfaces required some care in manufacture to develop proper contact. According to the instant invention, we have a novel arrangement of dovetail surfaces to provide three-area contact. This results in stability, fit and installation advantages.
It is to be appreciated that the element subject to wear may have to be replaced frequently--many times the base element to which it is attached outlasting a multiple of wearable elements.
Further, the prior art assembly of the base and wearable element was intended for installation in only one direction. This has not served the needs of operators in excavating, mining, etc. where reversibility is either required or is desirable. With the frequent replacement of the wearable element, it is advantageous to extend the life thereof by reversing the same.
Also, according to the instant invention, we achieve reversibility through a novel duplication of dovetail surfaces which makes possible the utilization, for example, of a single element where previously two different replacement elements had to be stored. For example, in the case of a bucket, it is advantageous to provide a wear element that wraps around a corner and thus, utilizing the patent teachings, it would be necessary to have both right and left hand styles. Now, through the practice of the invention, only a single, versatile replacement element is needed. This is a matter of some consequence to operators because buckets are usually employed in primitive conditions and storage facilities limited. Thus, anything that reduces the number of parts to be stored is highly desirable.
According to the preferred embodiment of the invention, each of the base and wear elements has a pair of longitudinally aligned and longitudinally spaced apart dovetail surfaces and a transversely spaced third dovetail surface positioned between the spaced pair of dovetail surfaces. One of the elements has a second pair of longitudinally aligned and longitudinally spaced apart dovetail surfaces flanking the third surface and a single surface interposed between the pair of surfaces. This permits reversible mounting of the two pair-equipped element on the one pair-equipped element, both mountings being "three point" for advantageous ease, stability, etc. Additionally, the three point mounting makes possible advantages in the installation and mounting of wearable parts on earth working equipment such as scraper mold boards. There each of the elements have longitudinally spaced apart dovetail surfaces in one outstanding wall and a single surface in an opposed outstanding wall portion.